Let’s Talk Bookish: Duologies vs. Trilogies

Let’s Talk Bookish is a weekly meme that was originally created and hosted by Rukky @ Eternity Books starting in August 2019, and was then cohosted with Dani @ Literary Lion from May 2020 to March 2022. Book Nook Bits has hosted since April 2022, with Dini at Dini Panda Reads as co-host from February 2025.

Let’s Talk Bookish July 4th:
Duologies vs. Trilogies

 Prompts: Do you prefer duologies or trilogies, and why? What are the pros and cons of having two books vs. three books in a series? What are some of your favourite duologies and/or trilogies? Do you think there are benefits to these shorter series, compared to ones with 4+ books, or are fewer books limiting?

Ooo this is a hard one. It kind of reminds me of a primary school teacher, whenever I was set homework to write a story (or…volunteered to write a story for homework. Yes, for ‘extra’ homework), and I’d ask, “Miss, how long does it have to be?” She’d tell me a story is whatever length a story needs to be – it’s like asking “how long is a piece of string”. Some stories are duologies. Some are trilogies, some are shorter and some are longer and they all, really, have their place.

To be honest…I don’t think I prefer one over the other. I’ve read the odd duology I wished was a trilogy so I could spend more time with the characters or seemed over too quickly, and I’ve occasionally read a trilogy that maybe felt a touch stretched out, and like it would have worked better as a duology, but in general, I quite like both. They serve different purposes – duologies often feel like one large book cut into two, while trilogies tend to feel a little more separated. I do appreciate with duologies how there isn’t that cliff-hanger ending with book 2, though.

Pros for duologies are that they’re quicker to get through – 2 books for a whole story! It can be less daunting that diving into a trilogy, especially if it’s a new to you author. Duologies can have a bit of a tighter, faster pace than trilogies, and don’t need to ‘pad’ anything out. For trilogies, well, 3 is the magic number, after all. Trilogies are great for when you want to spend more time in a world, or when there’s that bit more worldbuilding required for whatever reason. You can spend more ‘downtime’ with characters, if required, and get to know them better. Cons for duologies are related, really – sometimes they can be a little too fast, sometimes you don’t get to ‘know’ the characters as well, and sometimes it just isn’t enough! Cons for trilogies I’d say is that they can be a little slow at times, there seems to always be a A Big Cliff-hanger at the end of the second book, and sometimes you can be waiting a long, long time between books 1 and 3 being published, whereas duologies often feel like they come out a little closer together, too.

It’s been a while since I’ve read a complete trilogy, but off the top of my head some of my favourite duologies are Seven Devils, This Poison Heart, The Shadow Histories, The Never Tilting World, Great Cities and The Blood of Stars. For trilogies, I’d go with Folk of the Air, Hunger Games, Shades of Magic, and The Broken Earth. Keep in mind, too, there are plenty of duologies and trilogies I’ve started but not yet finished!

I think a trilogy is the maximum you can have for a self-contained story – once you go past that, the world and plot have to branch out a lot. There’s also a risk that the more books in a series, the more likely that there’ll be a few…not great ones. However, with a duology especially you have to really nail the ending, ensure everything is wrapped up – the same can be true in trilogies, but you have a bit more room to breathe. I do like when authors add to existing duologies/trilogies, setting stories in the same world or using a new trilogy to pick up with the characters later down the line, but this has to be handled very carefully. It also depends on the genre: romance can have a lot of long running series’ because you can focus on a different couple each book. With things like Urban Fantasy, crime, etc you can have a different ‘case’ per book, so these are more suited to a longer running series, and there doesn’t have to be a solid ‘end’ like there does for a duology/trilogy.

There are so many different types of book series, so many different ways they can be approached – it’s hard to cover them all! But what about you – are you a fan of duologies and trilogies, do you prefer longer running? How many books in a series is ideal, do you think? And what about your favourite book series – is that 2, 3, 7 books, more, incomplete?